Manual

C HAPTER T WO : Control by GPIB
WM-RCM-E Rev D ISSUED: February 2005 17
DEVICE CLEAR
In response to a universal Device CLear (DCL) or a Selected Device Clear message (SDC), the X-Stream DSO
clears the input or output buffers, cancels the interpretation of the current command (if any) and clears
pending commands. However, status registers and status-enable registers are not cleared. Although DCL will
have an immediate effect, it can take several seconds to execute if the oscilloscope is busy.
GROUP EXECUTE TRIGGER
The Group Execute Trigger message (GET) causes the X-Stream DSO to arm the trigger system, and is
functionally identical to the *TRG command.
REMOTE ENABLE
X-Stream DSOs do not lock out any local controls when placed in the remote state, or in RWLS. It always
accepts remote as well as local control inputs (unless you turn off remote control capability in UtilitiesÆ
Remote.)
INTERFACE CLEAR
The InterFace Clear message (IFC) initializes the GPIB but has no effect on the operation of the
X-Stream DSO.
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: To illustrate the GPIB programming concepts, a number of examples are included here,
written in a similar way to BASIC. It is assumed that the controller is IBM-PC compatible, and that it
is equipped with a National Instruments GPIB interface card. Nevertheless, GPIB programming with
other languages such as C or Pascal is quite similar. If you’re using another type of computer or
GPIB interface, refer to the interface manual for installation procedures and subroutine calls.
This procedure refers to the installation and configuration of a GPIB card under the DOS operating
system. More recent operating systems (Windows 95, 98, ME, NT, 2000, XP, etc) generally use ‘Plug
‘n’ Play’ GPIB drivers, which are configured using an icon in the control panel.
CONFIGURE THE GPIB DRIVER SOFTWARE
Verify that the GPIB interface is properly installed in the computer. If it is not, follow the interface
manufacturer’s installation instructions. In the case of the National Instruments interface, it is possible to
modify the base I/O address of the board, the DMA channel number, and the interrupt line setting using
switches and jumpers. In the program examples below, default positions are assumed.
Connect the X-Stream DSO to the computer with a GPIB interface cable.
Set the GPIB address to the required value. The program examples assume a setting of 4.